Investigation of the PLAG1 Rearrangement in Minor Salivary Gland Neoplasms with A Myoepithelial Component and Ectomesenchymal Chondromyxoid Tumor of the Tongue. A pilot study

A subset of ectomesenchymal chondromyxoid tumours of the tongue show EWSR1 rearrangements and are genetically linked to soft tissue myoepithelial neoplasms: a study of 11 cases

“…reported that 73% of cases of cutaneous and soft tissue myoepithelioma/mixed tumour with clear‐cut ductal structures harboured PLAG1 rearrangement. In a previous pilot study, we identified PLAG1 rearrangement in 33% of minor salivary gland plasmacytoid myoepitheliomas, 86% of pleomorphic adenomas with plasmacytoid predominance, and 0% of ECTs (cases 1–4; Table ) . In the current cohort, which included additional ECT specimens, we concluded that PLAG1 rearrangement is not detected in ECTs.…”

“…In a previous pilot study, we identified PLAG1 rearrangement in 33% of minor salivary gland plasmacytoid myoepitheliomas, 86% of pleomorphic adenomas with plasmacytoid predominance, and 0% of ECTs (cases 1-4; Table 1). 17 In the current cohort, which included additional ECT specimens, we concluded that PLAG1 rearrangement is not detected in ECTs. Our data suggest that PLAG1 gene abnormalities do not drive the tumorigenic events in this type of neoplasm, and therefore do not lend support to a cytogenetic linkage between ECT and plasmacytoid pleomorphic adenoma/myoepithelioma of minor salivary glands.…”

“…Previously, we investigated and compared the presence of PLAG1 rearrangement in a group of minor salivary gland myoepitheliomas and ECTs of the tongue by using fluorescence in‐situ hybridization (FISH) . None of the ECTs studied harboured PLAG1 aberrations, as opposed to the majority of intraoral salivary pleomorphic adenomas and a fraction of so‐called plasmacytoid myoepitheliomas.…”

“…None of the ECTs studied harboured PLAG1 aberrations, as opposed to the majority of intraoral salivary pleomorphic adenomas and a fraction of so‐called plasmacytoid myoepitheliomas. Hence, a cytogenetic relationship between ECT and pleomorphic adenoma/myoepithelioma of salivary gland origin could not be established …”

“…Hence, a cytogenetic relationship between ECT and pleomorphic adenoma/myoepithelioma of salivary gland origin could not be established. 17 In this study, we evaluated EWSR1 rearrangements in 11 ECTs of the tongue, to determine whether they have molecular similarities with soft tissue myoepithelial neoplasms. Additionally, we sought to confirm the findings of our pilot study regarding the PLAG1 rearrangement status of ECT by increasing the number of cases studied.…”